1. Field of the Invention
The present invention is broadly concerned with a method and apparatus for pre-lubrication of internal combustion engines in order to ameliorate the wear which occurs during ignition thereof. More particularly, it is concerned with such a pre-lubrication system having a pressurized, separate, valve-controlled oil accumulator vessel serving to lubricate vital internal engine components during an engine ignition sequence.
2. Description of the Prior Art
Modern four-stroke internal combustion engines normally have a pressurized oil circulation system for lubricating vital internal parts. These vital parts include valves, piston rings, crankshaft bearings, cam shafts, and related assemblies. The oil circulation system itself typically originates in an oil sump reservoir that is located beneath the crankshaft. The engine normally has an oil pump with an intake suction that pulls oil from a sump reservoir. The pump directs the oil first through a filter for cleaning and then through various oil galleys. The clean oil discharges from the galleys to lubricate the vital internal engine parts before returning to the sump.
If the engine operates while there is an insufficient supply of lubricating oil, the vital parts can quickly suffer premature wear from friction. For this reason, most engine designs include a pressure sensing device that is connected to the oil circulation galleys downstream of the oil pump. This pressure sensing device connects with either a gauge or a warning light in the operator's instrumentation panel.
Every one of the above-described internal combustion engines has a major flaw--a flaw that is standard in industry design. The oil pump only operates when the engine is running. Whenever an operator cranks the engine from a cold start, the vital parts move with diminished lubrication until the oil pump generates a sufficient volume and rate of flow. Experts estimate that perhaps as much as eighty percent of all engine wear occurs as a consequence of cold starting.
At least one manufacturer has attempted to address this problem. The design employed requires the installation of a second, electrically operated pump coupled with an intake line that is installed by tapping through the bottom of the sump. It is, however, disadvantageous to tap through the oil sump, because if the fitting becomes loose or is damaged then oil can drain from the lubrication system with catastrophic results. This system is also relatively expensive and difficult to install.